TC 14E II 1.4 Tele Enhanced Telephoto VersatilityAffordable and portable gateway to extend telephoto reach ideal for sports, wildlife, surveillance and more. 1.4x Optical Conversion FactorIncreases the focal length by 40% of select compatible NIKKOR lenses. Nikon Integrated Coating IC Enhances light transmission efficiency, improves color consistency and reduces flare. Advanced Optical Design5 elements in 5 groups optimized for use with FX and DX digital SLRs, engineered to meet the needs of professional photographers.